This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 94 |
| 6 | 512 |
| 7 | 3485 |
| 8 | 29515 |
| 9 | 314474 |
| 10 | 4255727 |
| 11 | 73831813 |
| 12 | 1653083021 |
| 13 | 47941962135 |
| 14 | 1803010446411 |
| 15 | 87882300251730 |
| 16 | 5543501326580737 |